Flow rates for taps are expressed on the water rating label in litres per minute (L/min).
The most water efficient taps have a 6 star WELS rating demonstrating a flow rate of 4 litres per minute or less.
Tapware products are tested for:
• endurance of tap components 50,000 on/off cycles
• hydraulic strength
• torque of joints
• water consumption
• water temperature test from hot to cold and back again every 55 cycles.
Flow rates for taps will be expressed on the water rating label in litres per minute (L/min).
Every 1L/min difference can save a household nearly 2,000 litres (2kL) of water and $5.50 each year.
Replacing an old inefficient tap with a flow rate of 15L/min with a new:
• 3-star tap that flows at 9L/min will save 11kL and $33 each year on water bills
• 6-star tap that flows at 4L/min will save 20kL and $60 each year on water bills.
Depending on energy costs, they may save an equivalent amount (or more) each year on energy bills because less water will be heated.
Assumptions: tap runs for 5 minutes total per day, for tasks including handwashing, tooth brushing, rinsing dishes, rinsing fruit or vegetables, at an average water price of $2.99/kL (the national average price reported in the 2014–15 Australian Bureau of Statistics Water Account). Time the tap is running to fill a basin is not included.